client's log:-
==========================================================================================================
<:: TFTPClient ::> mode test
Hostname: localhost and port : 6800. 
	MODE = Test
<:: TFTPClient ::> get test.doc
Invalid block number. Ending transaction.
<:: TFTPClient ::> get test.doc
The Data packet # 1 (512 bytes) is recieved from the sever.
Sending Ack block # 1
The Data packet # 2 (512 bytes) is recieved from the sever.
Sending Ack block # 2
.
.
.
The Data packet # 150 (512 bytes) is recieved from the sever.
Sending Ack block # 150
The Data packet # 151 (0 bytes) is recieved from the sever.
Sending Ack block # 151
The file has been read from the server.
<:: TFTPClient ::> 

error sim's log:-
============================================================================================================
rules> mangle data-1 block
rules> go
30.8: Dispatcher: Starting loop.
.
.
.
34.7: Relay[Server[51456]->Client[51453]]: Sending MANGLEBLOCK RAW PACKET to /127.0.0.1:51453
34.8: Relay[Client[51453]->Server[51456]]: Sending NORMAL ERROR 4 'Invalid Block number' to /127.0.0.1:51456
34.8: Session[Client[51453]<->Server[51456]]: Received ERROR, closing relays.
34.8: Relay[Client[51453]->Server[51456]]: Finished.
34.8: Relay[Server[51456]->Client[51453]]: Finished.

server's log:-
=============================================================================================================
04/04/08 12:48 AM :: RRQ from /127.0.0.1:51455 Started
04/04/08 12:48 AM :: Received ERROR 4Invalid Block number from /127.0.0.1:51455
04/04/08 12:48 AM :: Invalid Packet from /127.0.0.1:51455 Expected ACK, received ERROR
04/04/08 12:48 AM :: Unknown Error
04/04/08 12:48 AM :: RRQ from /127.0.0.1:51455 Completed


04/04/08 12:52 AM :: RRQ from /127.0.0.1:51467 Started
04/04/08 12:52 AM :: RRQ from /127.0.0.1:51467 Completed